My vitamin D levels are low, should I take a supplement?

By Peter Ebeling, University of Melbourne

If your blood test results suggest you’re low on vitamin D, you’re not alone – nearly one-third of the Australian population isn’t getting enough of the sunshine vitamin. But this doesn’t necessarily mean you need to take a supplement.

Contrary to some reports, there is no evidence that taking vitamin D supplements reduces your risk of developing diabetes, colon cancer, arthritis or infections, or that supplements help you live longer.

In some cases, taking a supplement merely means you’re wasting your money. But if you’re taking high doses, you may be doing more harm than good.

What is vitamin D?

Vitamin D is a fat soluble vitamin that is not readily available in the diet, apart from in fatty fish, ultraviolet (UV) light-irradiated mushrooms and green leafy vegetables. In fact, an average diet only provides one-sixth of the daily requirement for vitamin D, or about 110 international units (IU).

In many countries, including the United States and Philippines, there is widespread vitamin D fortification of foods, including milk, bread, cereals and orange juice. This does not occur in Australia.

Instead, most circulating vitamin D is generated via the effects of sunlight and UV “B” radiation on a cholesterol precursor in the skin. This then circulates in the blood and is activated in the liver and kidneys to become a hormone.

Anyone with less than 50 nanomoles of vitamin D per litre (nmol/L) at the end of winter or in early spring are categorised as having low levels.

Vitamin D and health

Vitamin D aids the absorption of calcium from the gut and is very important for healthy bones and muscles in both children and adults. Low vitamin D levels cause rickets in children, and soft (osteomalacia) or thin bones (osteoporosis) in adults.

Boosting your vitamin D levels will help ensure your bones remain healthy as you get older. Image from shutterstock.com

What is less clear is whether low vitamin D levels are associated with other chronic diseases such as bowel cancer, diabetes, heart disease, arthritis, infections and the overall risk of dying. This is because these low vitamin D levels could either be the cause or result of ill health.

A recent study in Lancet Diabetes and Endocrinology shows that earlier findings, derived from studies in which patients with several different chronic diseases had low vitamin D levels, were not reinforced by higher-level evidence resulting from clinical trials using vitamin D supplements.

In these trials, vitamin D supplements were given to correct low levels and to reduce effects of these diseases. The only exception was that vitamin D supplements slightly reduced the risk of dying in the elderly.

This apparent disconnect between the two levels of evidence may mean that low vitamin D levels are a marker of ill health, but not a causative factor for these chronic diseases.

The research solution

Large trials of vitamin D supplements in people with low vitamin D levels are now underway. Our study is based at the Berghofer Queensland Institute of Medical Research and the University of Melbourne, and will track participants over ten years.

We will treat 25,000 people aged from 60 to 79 years with low vitamin D levels to see whether vitamin D supplements will reduce the risk of dying. We will also see whether supplements reduce the risk of developing chronic diseases such as colon cancer, arthritis, infections and diabetes, as well as falls and fractures.

Studies such as ours will also need to look at markers of underlying disease activity.

The answer

So while we are waiting for this new evidence, what can you do about your low vitamin D level?

If the level is mildly decreased, rolling up your sleeves and getting outside in the sun more often — say, for about ten minutes at 10am or 2pm in summer, or for about 30 minutes at midday in winter — might help.

At these times, the UV index is likely to be less than three, indicating such limited sun exposure will be relatively safe. You can check how much sun you need on the Healthy Bones Australia website.

Vitamin D doses of 1,000 or 2,000 international units (IU) per day are safe. Image from shutterstock.com

Boosting your vitamin D levels, combined with a good dietary calcium intake of at least three serves per day and weight-bearing exercise (which includes brisk walking) for 20 minutes four times a week, will also help ensure your bones remain healthy as you get older.

If you are unable to get outdoors, or you cover your skin for cultural reasons, have dark skin, osteoporosis or low bone density (thin bones), you may need to take a supplement. The usual dose is 1,000 or 2,000 international units (IU) per day for most people.

After taking daily vitamin D supplements for three months, your doctor can check if the levels have increased above the recommended level of 50 nanomoles per litre (nmol/L). Such doses are safe, but very large yearly doses are not recommended because they can actually increase the risk of falls and fractures.

Peter Ebeling receives funding from NHMRC.

This article was originally published at The Conversation. Read the original article.

Joint Pain Supplements - Are they worth it?

Image Source - which.co.uk

Which? research shows that some supplement manufacturers are making misleading claims on their products - as a result, people could be wasting money on unnecessary food supplements.

Other manufacturers use clever language and font sizes to exaggerate the effect that some ingredients have.

So although only a small minority of people actually need supplements, a third of adults in our survey told us they regularly take them. The supplements industry was valued at £385 million in 2012.

Misleading claims

The most popular supplements people take are multivitamins, glucosamine supplements for joint health, and probiotic tablets and drinks.

However, all health claims relating to glucosamine and joint health have been rejected by the EU. Claims that probiotics improve digestive health were also rejected.

In the past five years, products (food, drink and supplements) that want to carry a health claim have had to submit the evidence behind that claim to the EU's European Food Safety Authority (EFSA). More than 44,000 health claims were originally submitted, and only 248 have so far been approved by the EU.
 
Supplements for joints

The EFSA panel rejected claims that glucosamine and chondroitin help support healthy joints, help support flexible joints and reduce inflammation in joints. However, 94% of adults in our survey who take glucosamine supplements believe that glucosamine supports healthy joints and cartilage.

• Seven Seas JointCare Active heavily advertises the ingredients glucosamine, omega-3 and chondroitin on the front of the pack above the health claim 'supports muscles, bones & cartilage to keep you moving'. Underneath, in much smaller text, the packaging states 'with vitamins C & D, Manganese and Zinc' - these are the ingredients for which the health claim is authorised.
• Optima ActivJuice Juice for Joints advertises glucosamine on the front of the pack with the health claim 'helps improve joint cartilage function'. On the back of the pack it says '...with glucosamine & vitamin C to provide a refreshing way to maintain normal function of cartilage in joints, bone, skin, teeth and blood vessels'. But this claim is only approved for vitamin C, not glucosamine.

Optima ActivJuice and Seven Seas JointCare active told us that their claims refer only to the specific ingredients that they are authorised for.

Glucosamine supplements can cost up to £1 a day. A multivitamin that contains vitamin C, D, manganese and zinc - the active ingredients in these supplements - can cost as little as 3p a day. This works out as up to £354 cheaper a year.

To see other products we found that were misleading or confusing visit our gallery of food supplements you don't need.
 
Which? says

Which? executive director Richard Lloyd said: 'Which? campaigned for health claims on these products to be backed up by scientific evidence, so it’s disappointing that manufacturers are using clever language to imply unproven benefits.

We would like to see all ambiguous and exaggerated claims completely removed from all food supplement packaging, so consumers can feel confident they are getting a fair deal in the products they buy.' 

This Article was originally published at - which.co.uk